docs: record 0.8.5 acceptance and the 0.9 referral mechanism

Ticks Slice 0.8.5's acceptance criteria against the implemented
behavior, verified against the seed and service code rather than
assumed, and notes that the Bandit Blade's World Renown 3 gate is
deliberately unreachable until Slice 0.11 adds the milestones to
reach it.

Points Slice 0.9 at the concrete bypass mechanism that now exists
(BORIN_OFFER_IDS.hideBag's bypassConditions flag) instead of the
placeholder reference to "the quest/referral exception".

Also commits the slice's plan and research-notes documents, which
were untracked.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

docs/playable-slices/0.8.5-Reputation-Gated-Merchant-Offers.md

@@ -223,14 +223,20 @@ No large modal is required.
 
 ## 11. Acceptance Criteria
 
-- [ ] Merchant offers can define reputation/unlock requirements.
-- [ ] At least two offers visibly demonstrate locked states.
-- [ ] Requirements are shown to the player in English.
-- [ ] Server rejects purchases when requirements are not met.
-- [ ] New progression offers do not depend on level gates.
-- [ ] Quest/referral unlock support exists for Slice 0.9.
-- [ ] Reputation increase can visibly unlock a previously locked offer.
-- [ ] No generalized rules engine was added unnecessarily.
+- [x] Merchant offers can define reputation/unlock requirements.
+- [x] At least two offers visibly demonstrate locked states.
+- [x] Requirements are shown to the player in English.
+- [x] Server rejects purchases when requirements are not met.
+- [x] New progression offers do not depend on level gates.
+- [x] Quest/referral unlock support exists for Slice 0.9.
+- [x] Reputation increase can visibly unlock a previously locked offer.
+- [x] No generalized rules engine was added unnecessarily.
+
+> **Note (implementation):** The Bandit Blade offer is gated on World Renown 3,
+> which current content cannot reach — there is one renown milestone, worth +1.
+> It is deliberately left visible and locked as a long-horizon goal until
+> Slice 0.11 adds the milestones that reach it (§5: visible rewards create
+> goals).
 
 ---
 

docs/playable-slices/0.9-First-Quest-and-Bag-Tutorial.md

@@ -133,7 +133,16 @@ Category: HIDE
 Capacity: 5
 ```
 
-The grant should use the quest/referral exception supported by Slice 0.8.5.
+The grant uses the referral exception built in Slice 0.8.5: the Basic Hide Bag
+offer (`BORIN_OFFER_IDS.hideBag`) carries
+
+```text
+bypassConditions: [{ type: FLAG_SET, key: 'referred-by-south-gate-warden' }]
+```
+
+so setting that flag on the character's Borin state opens the offer without
+changing any reputation. The offer's own gate stays at Border Watch
+Reputation 40.
 
 ---